Energy from Waste
This page discusses how to use waste to make energy, specifically through the capture of landfill gas and waste to energy facilities. For waste to energy, the discussion is limited to the application that is “a component of conventional municipal solid waste plant technology in commercial use”, as defined by the General Laws of Massachusetts.
Landfill gas is the natural by-product of the decomposition of solid waste in landfills and is comprised primarily of carbon dioxide and methane, which is then combusted to generate electricity. By preventing emissions of methane, which is a powerful greenhouse gas, landfill gas energy projects help communities protect the environment and build a sustainable future. Waste to Energy is referred to as the combustion of municipal solid waste to generate electricity.
How Does Landfill Gas Energy Work
Landfill gas is collected from landfills by drilling "wells" into the landfills, and collecting the gases through pipes. Once the landfill gas is processed, it can be combined with natural gas to fuel conventional combustion turbines. Specific combustion technologies include: Reciprocating Internal Combustion Engine (most common technology used), Gas Turbine, and Microturbine. Figure 1 is an illustration of how landfill gas energy systems work. Collected landfill gas can also be piped outside the landfill for direct use in systems such as boilers, kilns and greenhouses.
Figure 1: Landfill Gas Energy System. Source: Environment Canada
- Reduced Greenhouse Gas Emissions from Existing Landfills: Landfills are the second largest source of methane emissions in the United States. Capturing and destroying methane with landfill gas technologies can substantially reduce the amount of methane emitted to the atmosphere.
- Avoid Emission of Other Harmful Pollutants from Landfills: Emissions of pollutants such as mercury, lead, and particulate matter are reduced as the result of applying landfill gas and waste to energy technologies.
- Generate Revenue for Municipality: By converting waste and landfill gas to energy, municipalities can both save money on energy bills, and generate revenues from power sales of renewable energy certificates (RECs) or potential carbon credits.
- Potential Discouragement of Waste Reduction Measures: To keep the waste power generation facility viable, there needs to be constant waste feedstock. Therefore, there is a potential risk of discouraging efforts to reduce waste generation. However, the primary purpose of waste energy projects is to recover the energy that would otherwise be buried in the existing landfills.
- Small Amount of Dioxins Generated: Dioxins are known carcinogens.
The combustion of landfill gas does generate a small amount of dioxins.
Before initiating a landfill gas project, here are some important things to consider:
|Landfill Gas Checklist
|Step 1 - Conduct a Site Assessment: Perform a project feasibility study to evaluate if there is enough qualified landfill gas to run the generator on a regular basis.|
|Step 2 - Consider Choosing a Project Partner: Decide if you want to develop the
project with a private partner. Having a partner means that the local
government can receive royalties from the partner and also have the
partner share some of the project risks.
||Step 3 - Secure Project Financing: See below for more information on Financing options.
|Step 4 - Explore the Use of RECs or Carbon Credits: Landfill gas projects are eligible for Massachusetts and other New England Renewable Portfolio Standard (RPS) programs. In addition, these projects can sell Regional Greenhouse Gas Initiative (RGGI) offsets if they are not required to flare. If you want to enter the carbon market with a landfill gas project, you need to plan to do so at the early stage, including budgeting for and installing methane destruction monitoring and reporting systems.|
|Step 5 - Identify Utility Interconnection Requirements: Speak with your local utility to determine what options exist for connecting your landfill gas capture system to the electric grid Projects up to 60 kW in size are eligible for net metering.|
|Step 6 - Discuss Insurance & Liability Issues: Work with your municipal legal team to identify what types of insurance and liability coverage are required.|
|Step 7 - Conduct Public Outreach: To ensure as little resistance as possible, hold community forums to educate citizens about your landfill gas capture project. Provide information on how this will make your community more sustainable, provide an electricity source, provide an educational opportunity for local schools, and any other local priorities.|
If obstacles arise through the process listed above, consider working with appropriate agencies to modify existing regulations, ordinances/bylaws, zoning, etc. However, multiple obstacles may indicate that this energy type is not suitable for your community. If this is the case, consider another clean energy type.
Waste to Energy
For communities considering a waste to energy facility, please note that since 1990, the Commonwealth of Massachusetts has imposed a moratorium on the construction of new capacity for incinerating waste. The moratorium was originally established to avoid over-building in-state disposal capacity with facilities that require large amounts of waste. The Massachusetts Department of Environmental Protection (MassDEP) has maintained the moratorium on increased waste to energy facilities due to concerns about mercury emissions.
However, for communities outside of Massachusetts, there are two main types of waste to energy technologies: mass burn and refuse-derived fuel technology. Mass Burn technology is the direct combustion of municipal solid waste, where the energy derived from the combustion process converts water to steam. This steam is then used to drive a turbine connected to an electricity generator, thereby creating electricity.
Conversely, refuse-derived fuel technology processes municipal solid waste before combustion. The processing includes shredding municipal solid waste and removing metal and other bulky items. This process can increase the surface area of the waste and increase the combustion efficiency. The processed waste is then combusted in the same way as in mass burn technology.
For more information on the role of waste to energy facilities in Massachusetts, to learn about revisions to the Solid Waste Master Plan, and to view the proposed regulations, please visit the Massachusetts Department of Environmental Protection.
- Clean Air Act and MACT regulation: EPA imposes strict air emissions standards on waste to energy plants by requiring maximum achievable control technologies (MACT).
- Massachusetts Renewable Portfolio Standards: Landfill gas is defined as Class I renewable energy, and waste to energy is defined as Class II renewable energy in Massachusetts.
- Green Communities Act: Among other provisions, the Green Communities Act enables the Massachusetts Renewable Energy Trust to continue funding clean energy projects, including landfill gas initiatives.
- Municipal Waste Combustors: MassDEP provides an overview of municipal waste combustors, including how they operate and are regulated, and the progress they are making toward reducing emissions of targeted air pollutants.
- Green Communities Division: The Green Communities Act provides up to $10M annually in grants and loans for communities that qualify as a Green Community as specified in the Act. The Green Communities Division in DOER is developing guidelines for qualifying communities and administering the program. Funds are available to qualifying communities for renewable energy projects.
- Chicopee, MA: partnered with Ameresco Energy Services to develop a 5.7 MW landfill gas project that has the capacity to generate 49,932,000 kWh per year, enough to power over 3,700 homes and offsets 19,038 tons of equivalent CO2 emissions.
- Covanta Haverhill Ward Hill Neck Landfill, Haverhill, MA: All closed capped areas of the landfill are equipped with a landfill gas (LFG) collection system. The LFG system serves to collect landfill gas generated from MSW waste, prevent odors from being emitted to the surrounding community, and prevent greenhouse gas (methane) emissions.
- Fitchburg-Westminster Landfill Gas Energy Project, Fitchburg, MA: Waste Management, Inc. worked with the City of Fitchburg to convert the closed landfill to an energy source, allowing the captured methane to produce enough energy to power 3,000 homes. The gas from this project is co-fired with the biomass plant located in Westminster to produce electricity.
- Glendale Road Landfill Gas Project, Northampton, MA: As a project partner, Ameresco Inc. helped the City of Northampton develop an 800 kilowatt landfill gas project in 2008. The project uses a reciprocating engine to process methane collected from the city owned landfill. The landfill receives 50,000 tons of waste each year, and is about to close in 2010. The project is connected to the local grid, and generates enough electricity to power 600 homes annually.
- EPA Landfill Methane Outreach Program (LMOP): This EPA program maintains a database of current and candidate landfill gas projects all over the United States. The program also provides technical assistance and other services to municipalities on landfill gas technologies and projects.
- Integrated Waste Services Association: Website that provides information on waste to energy technologies and related environmental and health issues.
- Landfill Gas Energy Project Development Handbook: This online handbook gives step by step instructions on developing a landfill gas energy project. It includes an incredible amount of information on the details of project development.
- Massachusetts Landfill Gas to Energy Projects: This resource provides an overview of methane capture systems in Massachusetts that produce electricity which is sold to the grid.
- Power Scorecard: Website describing how each electricity generation technology works, and their environmental impacts.